Composite members, joints, and holding devices

Abstract

To provide a technique for improving the thermal conductivity of a composite member.SOLUTION: A composite member comprises aluminum nitride and silicon carbide, wherein when a distribution diagram of silicon, a distribution diagram of carbon, and a distribution diagram of aluminum in a cross-sectional view of the composite member obtained by an energy dispersive X-ray spectroscopy (EDS) method are superimposed, the composite member has: a region where silicon and carbon overlap and a region where silicon and carbon do not overlap in the distribution region of silicon; and a region where silicon and aluminum overlap in a region where silicon and carbon do not overlap.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a composite member, a joined body, and a holding device.

Background Art

[0002] Conventionally, composite members made of multiple materials have been known. For example, Patent Documents 1 and 2 disclose composite members having silicon carbide as a main constituent phase and containing titanium silicide, titanium silicon carbide, etc. Further, Patent Document 3 discloses a composite member having titanium silicide as a main constituent phase and containing silicon carbide, titanium carbide, etc.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, even with the prior art such as Patent Documents 1 to 3, there was still room for improvement in the technology for improving the thermal conductivity in composite members. For example, the composite members described in Patent Documents 1 and 2 contain silicon carbide as particles, and the composite member described in Patent Document 3 contains titanium silicide as particles. Therefore, gaps that become heat transfer resistances are likely to be formed between the particles inside the composite member, and variations in thermal conductivity occur depending on the dispersion state of the particles. Therefore, there was a risk that the thermal conductivity of the composite member would be low.

[0005] An object of the present invention is to provide a technology for improving the thermal conductivity in a composite member.

Means for Solving the Problems

[0006] The present invention has been made to solve at least some of the above-mentioned problems and can be realized in the following forms.

[0007] (1) According to one embodiment of the present invention, a composite member is provided. This composite member comprises aluminum nitride and silicon carbide, and when the silicon distribution map, carbon distribution map, and aluminum distribution map of the cross-section of the composite member obtained by energy-dispersive X-ray spectroscopy (EDS method) are superimposed, the silicon distribution region has a region where silicon and carbon overlap and a region where silicon and carbon do not overlap, and inside the region where silicon and carbon do not overlap, there is a region where silicon and aluminum overlap.

[0008] According to this configuration, when the silicon distribution map, carbon distribution map, and aluminum distribution map of the cross-section of the composite member obtained by the EDS method are superimposed, the silicon distribution region has areas where silicon and carbon overlap and areas where silicon and carbon do not overlap. In other words, silicon carbide, which has relatively high thermal conductivity, is unevenly distributed. On the other hand, inside the areas where silicon and carbon do not overlap, there are areas where silicon and aluminum overlap. In other words, aluminum nitride, which has relatively high thermal conductivity, is present in the areas where silicon carbide is not present. As a result, the composite member as a whole will contain either silicon carbide or aluminum nitride, which have relatively high thermal conductivity, thus reducing variations in thermal conduction within the composite member and improving thermal conductivity.

[0009] (2) In the composite member of the above form, the composite material may include a titanium compound. With this configuration, since the composite member contains a titanium compound, the coefficient of thermal expansion of the composite member formed from aluminum nitride and silicon carbide can be controlled. As a result, for example, when the composite member is joined to another member that becomes hot and the composite member is used as a heat dissipation member, the difference in thermal expansion can suppress the other member from peeling off from the composite member. As a result, the composite member can efficiently dissipate heat from the other member and maintain the bonded state with the other member.

[0010] (3) In the composite member of the above form, the thermal conductivity may be 80 W / (m·K) or higher. With this configuration, in the region of the composite member where silicon carbide is absent, there is aluminum nitride with a relatively small particle size. This makes it possible to make the thermal conductivity of the entire composite member 80 W / (m·K) or higher.

[0011] (4) According to another embodiment of the present invention, a joint is provided. This joint comprises the composite member described above and a ceramic material to be joined to the composite member. In this configuration, the joint comprises a composite member that conducts heat well and a ceramic material to be joined to it. As a result, the heat of the ceramic material can be efficiently dissipated through the composite member, thereby suppressing damage to the joint due to heat.

[0012] (5) In the above-described configuration of the joint, the composite member and the ceramic material may be joined by a metal joint. With this configuration, the composite member and the ceramic material are joined by a metal joint, which conducts heat relatively well. As a result, the heat from the ceramic material is transferred relatively easily to the composite member, and the heat from the ceramic material can be dissipated more efficiently through the composite member. Therefore, damage to the joint due to heat can be suppressed.

[0013] (6) According to yet another embodiment of the present invention, a holding device is provided. This holding device comprises the above-described joint, wherein the ceramic material has a chuck electrode, and the composite member has a cooling function. With this configuration, the holding device can hold an object using the chuck electrode of the ceramic material. At this time, the heat from the ceramic material is transferred to the composite member, which is a good conductor of heat, and can be released to the outside of the joint by the cooling function of the composite member. This makes it possible to suppress damage to the holding device due to heat.

[0014] Furthermore, the present invention can be realized in various forms, for example, in the form of a method for manufacturing composite members and joined bodies, an apparatus equipped with composite members and joined bodies, a system equipped with a holding device, and a control method for these apparatuses and systems. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view of the holding device of the first embodiment. [Figure 2] This is a cross-sectional view of the holding device according to the first embodiment. [Figure 3] This is the first diagram illustrating the cross-section of the composite member. [Figure 4] This is the second diagram illustrating the cross-section of the composite member. [Figure 5] This is the third diagram illustrating the cross-section of the composite member. [Figure 6] This diagram illustrates the raw material mixing ratios in the samples used in the evaluation test. [Figure 7] This is a diagram illustrating the results of the evaluation test. [Modes for carrying out the invention]

[0016] <First Embodiment> FIG. 1 is a perspective view of a holding device 100 according to the first embodiment. FIG. 2 is a cross section of the holding device 100 according to the first embodiment. The holding device 100 according to the first embodiment is, for example, an electrostatic chuck that holds a wafer W by adsorbing it with an electrostatic attraction force, and is provided in an etching device or the like. The holding device 100 includes a joined body 1 having a ceramic material 10, a composite member 20, and a joining portion 30. In the joined body 1, as shown in FIG. 1, the ceramic material 10, the joining portion 30, and the composite member 20 are laminated in this order from the plus side in the z-axis direction (lamination direction). In the present embodiment, the joined body 1 is a columnar body having a substantially circular cross-sectional shape perpendicular to the lamination direction. Note that each figure schematically shows the arrangement of each part and does not accurately represent the ratio of the dimensions of each part.

[0017] The ceramic material 10 is a substantially circular flat plate member formed of alumina (Al2O3). The ceramic material 10 has a pair of main surfaces 10a and 10b (see FIG. 2). On one of the pair of main surfaces 10a and 10b, a placement surface on which the wafer W is placed is formed. The wafer W placed on the placement surface is attracted and fixed to the placement surface by an electrostatic attraction force generated by a chuck electrode 11 disposed inside the ceramic material 10. A heater electrode (not shown) for heating the wafer W attracted and fixed to the placement surface may be incorporated inside the ceramic material 10. Note that the material forming the ceramic material 10 may be aluminum nitride (AlN), zirconia (ZrO2), silicon nitride (Si3N4), silicon carbide (SiC), yttria (Y2O3), or the like.

[0018] The composite member 20 contains aluminum nitride (AlN), silicon carbide (SiC), and a titanium compound. The composite member 20 of the present embodiment contains TiSi2 and Ti3SiC2 as the titanium compound. The ease of thermal expansion of the composite member 20 is determined by the ease of thermal expansion of the titanium compound. Therefore, by including the titanium compound, the degree of thermal expansion of the composite member 20 can be adjusted. In the present embodiment, the difference between the thermal expansion coefficient of the composite member 20 and the thermal expansion coefficient of the ceramic material 10 is 0.3×10 -6It is within / K. The thermal conductivity of the composite member 20 is 80 W / (m·K) or more. As shown in FIG. 2, the composite member 20 has a plurality of refrigerant flow paths 21 for the refrigerant to flow through. The details of the composite member 20 will be described later.

[0019] The joint portion 30 is disposed between the other main surface 10b of the pair of main surfaces 10a and 10b of the ceramic material 10 and the composite member 20. The joint portion 30 joins the ceramic material 10 and the composite member 20. In the present embodiment, the joint portion 30 is a metal compound made of Al-Mg. Thereby, heat is easily transferred between the ceramic material 10 and the composite member 20.

[0020] Next, a method for manufacturing the holding device 100 will be described. In manufacturing the holding device 100, first, each of the ceramic material 10 and the composite member 20 is produced. The ceramic material 10 is produced by using a slurry containing alumina powder to produce a plurality of green sheets. The produced green sheets are laminated while sandwiching a heater electrode, and a molded body having a substantially circular plate shape with a heater electrode built therein is produced. The produced molded body is fired under predetermined conditions to complete the ceramic material 10. Note that the ceramic material 10 may be produced by a press molding method.

[0021] For each of silicon carbide powder (average particle size 15.5 μm), silicon powder (average particle size 10.12 μm), titanium powder (average particle size 27 μm), and aluminum nitride powder (median value 15 μm) of the composite member 20, weighing is performed so as to obtain the following numbers. Silicon carbide: 15.0 mass% Silicon: 16.4 mass% Titanium: 38.8 mass% Aluminum nitride: 29.8 mass%

[0022] In the fabrication of the composite member 20 of this embodiment, a slurry is prepared by mixing these weighed powders to create multiple green sheets. The prepared green sheets are stacked to create a molded body having a space inside that serves as a refrigerant channel. The prepared molded body is fired under predetermined conditions (firing temperature: 1400°C, firing time: 4 hours, firing atmosphere: vacuum atmosphere) to complete the composite member 20. Finally, the ceramic material 10 and the composite member 20 are joined with a metal compound consisting of Al-Mg to complete the holding device 100. The composite member 20 may also be fabricated by press molding.

[0023] Figure 3 is the first diagram illustrating the cross-section of the composite member 20 of the first embodiment. Figure 3 is a schematic diagram showing the cross-section of the composite member 20 as imaged using a scanning electron microscope (SEM). The cross-sectional view shown in Figure 3 shows the region where silicon is present (region R1 shown by hatching with closely spaced dots), the region where titanium is present (region R2 shown by hatching with widely spaced dots), the region where aluminum nitride is present (region R3 shown by hatching with a dashed line), and the region where silicon carbide is present (region R4 shown by hatching with multiple horizontal lines). The region where silicon is present, the region where titanium is present, the region where aluminum nitride is present, and the region where silicon carbide is present in the cross-section of the composite member 20 are distinguished by comparing the cross-section as shown in Figure 3 with the results of energy-dispersive X-ray segregation for the same cross-section.

[0024] In Figure 3, regions R1 and R2 contain titanium silicide (TiSi2) and titanium silicon carbide (Ti3SiC2) produced by the reaction of silicon carbide and titanium used as raw materials. In the cross-section of the composite member 20, the aluminum nitride (region R3) is classified into aluminum nitride particles Pa1 with a particle size of 2 μm or larger, centered around aluminum nitride particles with a particle size of approximately 15 μm, which is the particle size of the aluminum nitride particles used as raw materials, and aluminum nitride lumps Pa2 that are smaller than 2 μm in size. As shown in Figure 3, the aluminum nitride lumps Pa2 are dispersed in region R1 where silicon is present (see region A1 enclosed by the dotted line in Figure 3). In the composite member 20 of this embodiment, by using aluminum nitride powder as a raw material in the range of 15 mass% to 50 mass% during the manufacturing of the composite member 20, it becomes easier to include lumps Pa2 that are smaller in size than the particle size of the raw material.

[0025] Figure 4 is a second diagram illustrating the cross-section of the composite member 20 of this embodiment. Figure 4 shows the distribution maps of silicon, carbon, and aluminum obtained when the cross-section of the composite member 20 is analyzed by energy-dispersive X-ray spectroscopy, in separate figures. The three figures in Figure 4 are schematic diagrams of the elemental distribution obtained by energy-dispersive X-ray spectroscopy at the same location, showing the portion where the X-ray intensity specific to each atom exceeds a certain level. From Figure 4, it can be expected that the carbon distribution region Dc partially overlaps with the silicon distribution region Ds. In the elemental distribution of aluminum shown in Figure 4, aluminum nitride particles Pa1 with a particle size of about 15 μm and aluminum nitride lumps Pa2 with a size of about 1 μm are shown, as explained in Figure 3.

[0026] Figure 5 is a third diagram illustrating the cross-section of the composite member 20 of this embodiment. Figure 5 shows the silicon distribution map, carbon distribution map, and aluminum distribution map of the cross-section of the composite member 20 shown in Figure 4, superimposed on each other. As shown in Figure 5, when the silicon distribution map, carbon distribution map, and aluminum distribution map of the cross-section of the composite member 20 obtained by energy-dispersive X-ray spectroscopy are superimposed on each other, the silicon distribution region Ds has a region Dsc1 where silicon and carbon overlap and a region Dsc0 where silicon and carbon do not overlap, and inside the region Dsc0 where silicon and carbon do not overlap, there is a region Dsa1 where silicon and aluminum overlap (regions Dsc1 and Dsc0 are each enclosed by thick solid lines in Figure 5). This region Dsa1 where silicon and aluminum overlap corresponds to the aluminum nitride blobs Pa2 shown in Figure 3, which are smaller than 2 μm in size. The region Dsa1 where silicon and aluminum overlap is presumed to have been formed during the firing process of the composite member 20, when a solid solution was formed between the silicon carbide particles and aluminum nitride particles, and a portion of the molten aluminum nitride penetrated into the silicon carbide structure. In the composite member 20 of this embodiment, as shown in Figure 5, when the silicon distribution region Ds is viewed using scanning electron microscopy (SEM), the area of ​​the region Dsa1 where silicon and aluminum overlap is smaller than the area of ​​the region Dsc1 where silicon and carbon overlap.

[0027] Next, we will explain the evaluation test of composite materials. In this evaluation test, multiple composite materials with different concentrations of constituent phases were created by changing the mixing ratio of the raw materials used in the manufacture of the composite material, and the thermal conductivity of each was evaluated and compared.

[0028] Figure 6 illustrates the mixing ratio of raw materials in the composite material samples used in this evaluation test. First, the method of preparing the samples used in this evaluation test will be explained. In this evaluation test, four types of samples were prepared as the samples to be evaluated. Each of the four types of samples was prepared by mixing at least three of the five types of raw materials shown in Figure 6, molding the mixture, and firing it. Each of the five types of raw materials used had particles with the following particle sizes. SiC: 15.5μm (average particle size) Si:10.12μm (average particle size) Ti:27μm (average particle size) TiSi2: 5~10μm (average particle size) AlN: 15 μm (median)

[0029] As shown in Figure 6, Sample 1 does not use aluminum nitride as a raw material. Samples 2-4 have a higher amount of aluminum nitride than silicon carbide as a raw material. As mentioned above, when the amount of aluminum nitride as a raw material is in the range of 15% to 50% by mass, it tends to contain lumps of aluminum nitride smaller than the particle size of the raw material. Samples 2-4 all have an amount of aluminum nitride of about 30% by mass, and in their cross-sections, they tend to contain lumps of aluminum nitride smaller than the particle size of the raw material. Samples 1-4 shown in Figure 6 were prepared by firing in a vacuum atmosphere at a firing temperature of 1400°C for 4 hours.

[0030] Figure 7 illustrates the results of this evaluation test. Figure 7 shows the ratios (in mass%) of each of the five constituent phases and the thermal conductivity (in W / (m·K)) for each of the samples 1-4. The ratios of the five constituent phases in samples 1-4 were determined using an X-ray diffractometer (measurement conditions: CuKα, 40kV, 40mA, 2θ=5-70°) with samples ground in a mortar.

[0031] In this evaluation test, four types of samples were evaluated based on the thermal conductivity required for bonding with alumina, assuming a composite component to be bonded with alumina ceramic material. The thermal conductivity of alumina (Al2O3) is generally less than 30 W / (m·K). Therefore, when the samples are used as composite components to be bonded with alumina ceramic material, it is desirable that the thermal conductivity of the samples be 80 W / (m·K) or higher, which is more than twice the thermal conductivity of alumina. Hereinafter, a thermal conductivity of 80 W / (m·K) will be referred to as the "reference thermal conductivity." The thermal conductivity of the samples was measured using the laser flash method.

[0032] Sample 1 contained almost no aluminum nitride as a constituent phase, and its thermal conductivity was found to be lower than the reference thermal conductivity. On the other hand, Samples 2-4 contained more aluminum nitride than silicon carbide as a constituent phase, and their thermal conductivity was found to be higher than the reference thermal conductivity.

[0033] As described above, according to the composite member 20 of this embodiment, when the silicon distribution map, carbon distribution map, and aluminum distribution map of the cross-section of the composite member 20 obtained by the EDS method are superimposed as shown in Figure 5, the silicon distribution region Ds has a region Ds1 where silicon and carbon overlap and a region Ds0 where silicon and carbon do not overlap. This means that silicon carbide, which has relatively high thermal conductivity, is unevenly distributed. On the other hand, inside the region Dsc0 where silicon and carbon do not overlap, there is a region Dsa1 where silicon and aluminum overlap. In other words, in the composite member 20, in the region where silicon carbide is not present, there is a mass of aluminum nitride, which has relatively high thermal conductivity. As a result, the composite member 20 as a whole will have either silicon carbide or aluminum nitride, which have relatively high thermal conductivity, so the variation in heat conduction in the composite member 20 is reduced. Therefore, the thermal conductivity of the composite member 20 can be improved.

[0034] Furthermore, in general, composite members containing a large amount of silicon carbide particles have an uneven distribution of silicon carbide within the composite member. This results in non-uniform thermal conductivity within the composite member, and for example, when the composite member is used as a heat transfer material, there is a risk that heat will not be transferred uniformly. In the composite member 20 of this embodiment, in regions where silicon carbide is absent, a solid solution of silicon carbide and aluminum nitride is formed, resulting in the formation of multiple lumps of aluminum nitride with a particle size smaller than that of the raw materials. As a result, the silicon carbide particles and aluminum nitride lumps are dispersed in the cross-section of the composite member 20, making it easier to achieve uniform thermal conductivity within the composite member 20 and improving the uniformity of thermal conductivity within the composite member 20. Therefore, when the composite member 20 is used as a heat transfer material, heat can be transferred uniformly.

[0035] Furthermore, according to the composite member 20 of this embodiment, the inclusion of a titanium compound in the composite member 20 controls the thermal expansion coefficient of the composite member 20 formed from aluminum nitride and silicon carbide. In the joint 1, by making the thermal expansion coefficient of the composite member 20 close to that of the ceramic material 10, it is possible to suppress the delamination of the ceramic material 10 from the composite member 20 due to the difference in thermal expansion. As a result, the composite member 20 can efficiently dissipate the heat from the ceramic material 10, thereby improving the thermal conductivity of the composite member 20 and suppressing damage to the joint 1.

[0036] Furthermore, according to the composite member 20 of this embodiment, within the composite member 20, there is a region Dsc0 in which silicon and carbon do not overlap, that is, a region in which silicon carbide does not exist, and in which relatively small chunks of aluminum nitride are present. As a result, the thermal conductivity of the entire composite member 20 can be made 80 W / (m·K) or more, which is more than twice as high as the thermal conductivity of alumina.

[0037] Furthermore, according to the joint 1 of this embodiment, the joint 1 comprises a ceramic material 10 that is joined to a composite member 20 that easily conducts heat. As a result, the heat from the ceramic material 10 can be efficiently dissipated through the composite member 20, thereby suppressing damage to the joint 1 due to heat.

[0038] Furthermore, in the joint 1 of this embodiment, the composite member 20 and the ceramic material 10 are joined by a joint 30 made of metal, which is a relatively good conductor of heat. As a result, the heat from the ceramic material 10 is relatively easily transferred to the composite member 20, allowing the heat from the ceramic material 10 to dissipate more efficiently through the composite member 20. Therefore, damage to the joint 1 due to heat can be suppressed.

[0039] Furthermore, the holding device 100 of this embodiment is an electrostatic chuck that can hold the wafer W using the chuck electrodes 11 of the ceramic material 10. At this time, the heat from the ceramic material 10 is transferred to the composite member 20, which is a good conductor of heat, and can be released to the outside of the joint 1 by the coolant flowing through the coolant channel 21 of the composite member 20. This makes it possible to suppress damage to the holding device 100 due to heat.

[0040] <Modified form of this embodiment> The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit, for example, the following modifications are also possible.

[0041] [Example 1] In the above-described embodiment, the composite member 20 contained a titanium compound. The composite member does not necessarily have to contain a titanium compound, but the thermal expansion coefficient of the composite member can be adjusted by adjusting the content of the titanium compound.

[0042] [Differentiation 2] In the above-described embodiment, the thermal conductivity of the ceramic material 10 was set to 80 W / (m·K) or higher in order to facilitate heat dissipation when using the joint 1 as an electrostatic chuck, but the thermal conductivity of the composite member 20 is not limited to this.

[0043] [Difference 3] In the above-described embodiment, the joint 1 comprises a ceramic material 10, a composite member 20, and a joint 30, but the configuration of the joint 1 is not limited to this. The material forming the member to be joined with the composite member 20 is not limited to ceramics such as alumina. The joint does not have to be a metal joint. Any configuration that can utilize the high thermal conductivity of the composite member is acceptable.

[0044] [Differentiation Example 4] In the above-described embodiment, the joint 1 is used in a holding device 100, but the field to which the joint 1 is applied is not limited to this. It can be applied in any field where the high thermal conductivity of the composite material can be utilized.

[0045] The embodiments of this specification have been described above based on the embodiments and modifications described above. The embodiments described above are for the purpose of facilitating understanding of this specification and do not limit it. This specification may be modified and improved without departing from its spirit and the scope of the claims, and equivalents thereof are included in this specification. Furthermore, any technical features that are not described as essential in this specification may be deleted as appropriate.

[0046] (Application Example 1) It is a composite member, It contains aluminum nitride and silicon carbide, When the distribution maps of silicon, carbon, and aluminum in the cross-section of the composite material, obtained by energy-dispersive X-ray spectroscopy (EDS), are superimposed, Within the silicon distribution region, there are regions where silicon and carbon overlap and regions where silicon and carbon do not overlap. Inside the region where silicon and carbon do not overlap, there is a region where silicon and aluminum overlap. A composite member characterized by the following features. (Application Example 2) The composite member described in Application Example 1 is further, Contains titanium compounds A composite member characterized by the following features. (Application Example 3) A composite member as described in Application Example 1 or Application Example 2, The thermal conductivity is 80 W / (m·K) or higher. A composite member characterized by the following features. (Application Example 4) A joint, A composite member described in any one of Application Examples 1 to 3, The composite member comprises a ceramic material to which the composite member is joined, A joint characterized by the following features. (Application Example 5) A joint described in any one of the examples from Application Example 1 to Application Example 4, The composite member and the ceramic material are joined by a metal bond. A joint characterized by the following features. (Application Example 6) A holding device, The joint is provided as described in any one of the examples from Application Example 1 to Application Example 5, The aforementioned ceramic material has a chuck electrode, The composite member has a cooling function. A holding device characterized by the following features. [Explanation of Symbols]

[0047] 1...Holding device 10…Ceramic material 11... Chuck electrode 20… Composite materials 21… Refrigerant flow path

Claims

1. It is a composite member, It contains titanium compounds, aluminum nitride, and silicon carbide. Based on the results of quantitative analysis by X-ray diffraction for each of the SiC, TiSi2, Ti3SiC2, TiC0.62, and AlN contained in the composite member, when the sum of the masses of each of the SiC, TiSi2, Ti3SiC2, TiC0.62, and AlN contained in the composite member is taken as 100%, The total mass ratio of the titanium compounds TiSi₂, Ti₃SiC₂, and TiC₀.62 is between 53.3% and 56.9%. The ratio of aluminum nitride is 37.8% or more and 42.4% or less. The ratio of silicon carbide is 1.8% or more and 5.4% or less. When the distribution maps of silicon, carbon, and aluminum in the cross-section of the composite material, obtained by energy-dispersive X-ray spectroscopy (EDS), are superimposed, Within the silicon distribution region, there are regions where silicon and carbon overlap and regions where silicon and carbon do not overlap. Inside the region where silicon and carbon do not overlap, there is a region where silicon and aluminum overlap. The thermal conductivity is 80 W / (m·K) or higher. A composite member characterized by the following features.

2. A joint, The composite member according to claim 1, The composite member comprises a ceramic material to which the composite member is joined, A joint characterized by the following features.

3. The joint according to claim 2, The composite member and the ceramic material are joined by a metal bond. A joint characterized by the following features.

4. A holding device, The joint is provided as described in claim 2, The aforementioned ceramic material has a chuck electrode, The composite member has a cooling function. A holding device characterized by the following features.

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